"Early attempts to study snake navigation were awry because the studies used mazes as testing arenas -- as though snakes might be expected to run through mazes in the same way rats run through mazes," Peter Kareiva, a professor of zoology at the University of Washington, wrote last summer in Integrative Biology, of which he is editor-in-chief. "Of course, snakes do not encounter anything resembling mazes in nature, and they do not learn how to run mazes in laboratory conditions.
"The bottom line is that when tested in a biologically meaningful way, snakes exhibit spatial learning that rivals the learning abilities of birds and rodents," he concluded, "but the cues used by snakes [need] to match their ecology."
Holtzman found a few age-based differences in the cues snakes use to extricate themselves from the arena. Young snakes - - those up to three years old -- appear to be more adaptable and resourceful, using a variety of clues to find their way to the exit. But their elders seem to rely much more heavily on visual cues, becoming a bit befuddled if the brightly colored card marking the exit hole is tampered with.
"Actually, one of the interesting findings from our studies is that snakes use vision at all in locating places," says Holtzman. "They don't just rely on the chemical cues picked up by flicking their tongues out, as many snake biologists assume."
The experiments within the arena were surveyed by video
cameras that can detect tiny foil hats fitted to the bright
orange and red snakes, which can grow to lengths of four feet.
The snakes can't be observed directly during experimentation,
because the presence of a person might provide them a cue,
disrupting the experiment. Researchers lurk just out of sight
behind black curtains that wall off the arena, watching the
Contact: Tom Rickey
University of Rochester